ref: 9c93ef3bff67f0f3ded2856b612ec632f22b2d46
dir: /engine/battle/decrement_pp.asm/
DecrementPP: ; 68000 (1a:4000) ; after using a move, decrement pp in battle and (if not transformed?) in party ld a, [de] cp a, STRUGGLE ret z ; if the pokemon is using "struggle", there's nothing to do ; we don't decrement PP for "struggle" ld hl, W_PLAYERBATTSTATUS1 ld a, [hli] ; load the W_PLAYERBATTSTATUS1 pokemon status flags and increment hl to load the ; W_PLAYERBATTSTATUS2 status flags later and a, (1 << StoringEnergy) | (1 << ThrashingAbout) | (1 << AttackingMultipleTimes) ret nz ; if any of these statuses are true, don't decrement PP bit UsingRage, [hl] ret nz ; don't decrement PP either if Pokemon is using Rage ld hl, wBattleMonPP ; PP of first move (in battle) ; decrement PP in the battle struct call .DecrementPP ; decrement PP in the party struct ld a, [W_PLAYERBATTSTATUS3] bit Transformed, a ret nz ; Return if transformed. Pokemon Red stores the "current pokemon's" PP ; separately from the "Pokemon in your party's" PP. This is ; duplication -- in all cases *other* than Pokemon with Transform. ; Normally, this means we have to go on and make the same ; modification to the "party's pokemon" PP that we made to the ; "current pokemon's" PP. But, if we're dealing with a Transformed ; Pokemon, it has separate PP for the move set that it copied from ; its opponent, which is *not* the same as its real PP as part of your ; party. So we return, and don't do that part. ld hl, wPartyMon1PP ; PP of first move (in party) ld a, [wPlayerMonNumber] ; which mon in party is active ld bc, wPartyMon2 - wPartyMon1 call AddNTimes ; calculate address of the mon to modify .DecrementPP ld a, [wPlayerMoveListIndex] ; which move (0, 1, 2, 3) did we use? ld c, a ld b, 0 add hl ,bc ; calculate the address in memory of the PP we need to decrement ; based on the move chosen. dec [hl] ; Decrement PP ret